Answer:
The area needed to be painted is approximately 301.44 square inches.
Step-by-step explanation:
The shape of a donut is represented by two concentrical circles, whose area is described by the following formula:
(Eq. 1)
Where:
- Total area of the donut, measured in squared inches.
- Area of the greater circle, measured in square inches.
- Area of the lesser circle, measured in square inches.
By using the definition of the area of the circle, we expand the equation above:
(Eq. 1b)
If we know that
,
and
, the area needed to be painted is:
![A = \frac{(3.14)\cdot (22\,in)^{2}}{4}-78.5\,in^{2}](https://tex.z-dn.net/?f=A%20%3D%20%5Cfrac%7B%283.14%29%5Ccdot%20%2822%5C%2Cin%29%5E%7B2%7D%7D%7B4%7D-78.5%5C%2Cin%5E%7B2%7D)
![A \approx 301.44\,in^{2}](https://tex.z-dn.net/?f=A%20%5Capprox%20301.44%5C%2Cin%5E%7B2%7D)
The area needed to be painted is approximately 301.44 square inches.
Answer x=-26
3-3x=81
-3x=81-3
-3x=78
x=(78/-3)
x=-26
2x-6+1=3x+4
2x-5=3x+4
2x-3x=4+5
-x=9